Contamination of pharmaceuticals with microorganisms may lead to deleterious effects on the therapeutic properties of the drug, and may potentially cause injuries to intended recipients. Cases of contaminated nonsterile products have been reported in increasing numbers, and often associated with the presence of objectionable microorganisms. Methods for detection of these organisms are described in three major Pharmacopeias. Their functions and their limitations in the examination of microbiological quality for nonsterile products will be reviewed in this report.